含旋转部件目标稀疏孔径ISAR成像方法

针对稀疏孔径条件下含旋转部件目标(ISAR)成像质量较差的问题，提出了一种基于子孔径Chirplet变换和压缩感知(CS)的含旋转部件目标稀疏孔径ISAR成像方法：首先，建立了含旋转部件目标的稀疏ISAR成像模型，推导了宽带雷达条件下含旋转部件目标的微多普勒效应，并分析了孔径的稀疏与微多普勒效应共存时对成像的影响；其次将回波信号投影到Chirplet变换基，利用目标主体回波信号和微动部件回波信号在Chirplet变换投影参数上的差异，有效剔除有效子孔径中的微多普勒调制信号;最后，采用基于正交匹配追踪(OMP)算法的CS方法对有效子孔径进行恢复成像，获得了含旋转部件目标的高质量成像结果。仿真实验表明，该方法可以有效消除微多普勒效应和孔径稀疏的干扰，并实现高质量的ISAR成像。

Sparse-Aperture ISAR Imaging for Target With Rotating Parts

To solve the problem of the sparse-aperture ISAR imaging for the target with rotating parts is poorer, a method based on sub-aperture Chirplet transform and Compressed Sensing(CS) is proposed in this paper. Firstly, the sparse ISAR imaging model of the target with rotating parts is established, then the effect of micro-Doppler of the target with rotating parts in broadband radar is deduced, and then the influence of the sparse of aperture and the micro-Doppler together is analyzed. Secondly, the radar echoes are decomposed into a series of Chirplet basis, getting rid of the micro-Doppler signal in sub-aperture based on the difference of the Chirplet parameters of the echo signals of main parts and rotating parts. Finally, to recover the imaging from the subaperture based on the CS method of Orthogonal Matching Pursuit (OMP) algorithm, getting the high quality imaging results of the target with rotating parts. Simulations show the method could eliminate the micro-doppler effect and achieve high quality imaging.